Seriously, how do you see those first examples as manipulation, if you agree with him? You come to my door, and I invite you in--and he says I'm manipulating you by inviting you in, and then again by offering you a seat. All of those could be put into a subtext of manipulation, sure, as could your coming to my door, but without being placed in that subtext, how do you view them as being manipulative in and of themselves?
That's definitely not "manipulating at the worst". I have definitely seen people allow their kids to manipulate them like this, and sometimes the manipulation gets worse as a result (but astonishingly, not always). But I think he must have meant "at the worst" hyperbolically.
That's a different matter.